Package org.lwjgl.vulkan

Class EXTMultisampledRenderToSingleSampled

java.lang.Object
org.lwjgl.vulkan.EXTMultisampledRenderToSingleSampled
public final class EXTMultisampledRenderToSingleSampled extends Object
With careful usage of resolve attachments, multisampled image memory allocated with MEMORY_PROPERTY_LAZILY_ALLOCATED_BIT, loadOp not equal to ATTACHMENT_LOAD_OP_LOAD and storeOp not equal to ATTACHMENT_STORE_OP_STORE, a Vulkan application is able to efficiently perform multisampled rendering without incurring any additional memory penalty on some implementations.

Under certain circumstances however, the application may not be able to complete its multisampled rendering within a single render pass; for example if it does partial rasterization from frame to frame, blending on an image from a previous frame, or in emulation of GL_EXT_multisampled_render_to_texture. In such cases, the application can use an initial subpass to effectively load single-sampled data from the next subpass’s resolve attachment and fill in the multisampled attachment which otherwise uses loadOp equal to ATTACHMENT_LOAD_OP_DONT_CARE. However, this is not always possible (for example for stencil in the absence of VK_EXT_shader_stencil_export) and has multiple drawbacks.

Some implementations are able to perform said operation efficiently in hardware, effectively loading a multisampled attachment from the contents of a single sampled one. Together with the ability to perform a resolve operation at the end of a subpass, these implementations are able to perform multisampled rendering on single-sampled attachments with no extra memory or bandwidth overhead. This extension exposes this capability by allowing a framebuffer and render pass to include single-sampled attachments while rendering is done with a specified number of samples.

Name String
VK_EXT_multisampled_render_to_single_sampled
Extension Type
Device extension
Registered Extension Number
377
Revision
1
Extension and Version Dependencies
VK_KHR_create_renderpass2 and VK_KHR_depth_stencil_resolve or Version 1.2
Contact
Extension Proposal
VK_EXT_multisampled_render_to_single_sampled
Other Extension Metadata
Last Modified Date
2021-04-16
IP Status
No known IP claims.
Contributors
  • Shahbaz Youssefi, Google
  • Jan-Harald Fredriksen, Arm
  • Jörg Wagner, Arm
  • Matthew Netsch, Qualcomm Technologies, Inc.
  • Jarred Davies, Imagination Technologies